Fibrous materials such as straw from flax, sisal, hemp, jute and coir, banana, among others, are used or combined with various polymers in the formation of biocomposite or bio-fiber composite materials. Biocomposite materials utilizing these fibrous materials or fibers mixed with selected polymers provide enhanced desirable properties compared with polymer-only materials. For example, biocomposite materials have the advantageous qualities of light weight, enhanced strength, corrosion resistance, design flexibility, inexpensive production, and environmental friendliness, among others over materials only formed from polymers.
However, regardless of these many beneficial properties, when natural fibers or fibrous materials are utilized, odors are created from the breakdown of natural fibers during fiber processing, when the fibers are subjected to high temperatures. These odors can be retained in the biocomposite material after processing, making products formed from those biocomposite materials that utilize natural fibers undesirable. To attempt to address this issue, alternative fiber processing steps have been utilized that minimize the intensity and duration of the heat that the fibers are exposed to reduce the amount of odor emitted by the processing of the fibers. However, because the fiber must be exposed to heat at some point during processing in order to properly condition the fibers prior to use in forming the biocomposite material, these attempts have been unsuccessful.
Other attempts to alleviate the odors present in these types of fibrous materials utilize odor-reducing or eliminating additives such as, deodorants, fragrances, and antimicrobials that are intermixed directly with the fibrous material and incorporated into the biocomposite materials. Some examples of the incorporation of these type of odor eliminating agents, which normally take the form of oxidizing agents, such as hydrogen peroxide, are disclosed in US2007/0020542, US2012/0148518; and U.S. Pat. No. 5,562,740, each of which are expressly incorporated by reference herein in their entirety.
In these examples, while the fibrous materials including these coatings have reduced odors due to the presence of the oxidizing agents applied to the fibrous materials, the presence of the oxidizing agents adds an additional step to the treatment of the fibrous materials, and creates issues with regard to the recycling of the biocomposite materials as a result of the presence of the oxidizing agents.
As a result, it is desirable to develop a method for processing and/or modifying the natural fibers to remove unwanted odors that does not require additional steps in the processing off the fibrous materials and that does not require additives to be incorporated with the fibrous materials within the resulting biocomposite materials.